In the nondestructive testing of elongated relatively large and bulky parts by ultrasonic techniques, the part (workpiece) to be tested is located within a fluid bath (e.g., water) and a transducer is caused to scan from one end to the other of the part. On each scanning traversal of the ultrasonic transducer, the workpiece is rotated so that a different line of test may be achieved. Typically, the test information is stored for later use and evaluation, or the workpiece itself is marked at each defect location.